function Map() {
            this.keys = new Array();
            this.data = new Array();
            //添加键值对
            this.set = function (key, value) {
                if (this.data[key] == null) {//如键不存在则身【键】数组添加键名
                    this.keys.push(value);
                }
                this.data[key] = value;//给键赋值
            };
            //获取键对应的值
            this.get = function (key) {
                return this.data[key];
            };
            //去除键值，(去除键数据中的键名及对应的值)
            this.remove = function (key) {
                this.keys.remove(key);
                this.data[key] = null;
            };
            //判断键值元素是否为空
            this.isEmpty = function () {
                return this.keys.length == 0;
            };
            //获取键值元素大小
            this.size = function () {
                return this.keys.length;
            };
        }
        //例子
        var  bb = new Map();
        bb.set("cc", "dd");
        bb.set("dd", "ee");
        alert(bb.get("cc") + bb.get("dd"));